public class Example4_20 {	
	   public static void main(String args[ ]) { 
		   char a[]={'a','b','c','D','E','F'};
    		   for(int i=0;i<a.length;i++) { 
			   if(Character.isLowerCase(a[i]))    
				   a[i]=Character.toUpperCase(a[i]);
			   else if(Character.isUpperCase(a[i]))
				   a[i]=Character.toLowerCase(a[i]);
		   }
		   for(int i=0;i<a.length;i++)   
			   System.out.print(" "+a[i]);
	   } 
}

